UNITED STATES
SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 10-Q

QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934

For the quarterly period ended March 31, 2026

TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934

For the transition period from to

Commission File Number: 001-34800

ECA MARCELLUS TRUST I

(Exact name of registrant as specified in its charter)

Delaware		27-6522024
(State or other jurisdiction of incorporation or organization)		(I.R.S. Employer Identification No.)

The Bank of New York Mellon
Trust Company, N.A., Trustee
Global Corporate Trust
601 Travis Street, 16^th Floor
Houston, Texas		77002
(Address of principal executive offices)		(Zip Code)

(512) 236-6555
(Registrant’s telephone number, including area code)

Securities registered pursuant to Section 12(b) of the Act: None

Indicate by check mark whether the registrant (1) has filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during the preceding 12 months (or for such shorter period that the registrant was required to file such reports), and (2) has been subject to such filing requirements for the past 90 days. Yes x No ¨

Indicate by check mark whether the registrant has submitted electronically every Interactive Data File required to be submitted pursuant to Rule 405 of Regulation S-T (§232.405 of this chapter) during the preceding 12 months (or for such shorter period that the registrant was required to submit such files). Yes o No o

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, a smaller reporting company, or an emerging growth company. See the definitions of “large accelerated filer,” “accelerated filer,” “smaller reporting company,” and “emerging growth company” in Rule 12b-2 of the Exchange Act.

Large accelerated filer ¨

Accelerated filer ¨

Non-accelerated filer x

Smaller reporting company x

Emerging growth company ¨

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ¨

Indicate by check mark whether the registrant is a shell company (as defined in Rule 12b-2 of the Exchange Act). Yes ¨ No x

As of May 13, 2026, 17,605,000 Common Units of Beneficial Interest in ECA Marcellus Trust I were outstanding.

TABLE OF CONTENTS

PART I – Financial Information
Item 1. Unaudited Financial Statements	3
Statement of Assets, Liabilities and Trust Corpus as of March 31, 2026 (Unaudited) and December 31, 2025	3
Statement of Distributable Income for the Three Months Ended March 31, 2026 and 2025 (Unaudited)	4
Statement of Trust Corpus for the Three Months Ended March 31, 2026 and 2025 (Unaudited)	5
Notes to Financial Statements	6
Item 2. Trustee’s Discussion and Analysis of Financial Condition and Results of Operations	10
Item 3. Quantitative and Qualitative Disclosures About Market Risk	16
Item 4. Controls and Procedures	16
PART – II Other Information	18
Item 1A. Risk Factors	18
Item 5. Other Information	18
Item 6. Exhibits	18
SIGNATURES	19
APPENDIX A	20
Glossary of Certain Terms	20

References to the “Trust” in this document refer to ECA Marcellus Trust I. As discussed in Part I, Item 2 – “Trustee’s Discussion and Analysis of Financial Condition and Results of Operations – Overview,” in November 2017 Greylock Energy, LLC, and certain of its wholly owned subsidiaries acquired substantially all of the gas production and midstream assets of Energy Corporation of America, including all of the interests of Legacy ECA (as defined below) in certain natural gas properties that are subject to the royalty interests held by ECA Marcellus Trust I (the “Acquisition”). References to “Greylock Energy” in this document refer to Greylock Energy, LLC and certain of its wholly-owned subsidiaries, including Greylock Production, LLC (“Greylock Production”), which serves as operator of the subject wells, and Greylock Midstream, LLC (“Greylock Midstream”), whose subsidiaries market and gather certain of the gas. References to “Legacy ECA” in this document refer to Energy Corporation of America and its wholly-owned subsidiaries, and, when discussing the conveyance documents, the Private Investors (as defined in “Glossary of Certain Terms” in Appendix A), as such entities existed prior to the asset acquisition by Greylock Energy. References to the “Sponsor” in this document refer to Legacy ECA for periods prior to the Acquisition, and to Greylock Energy for periods after the Acquisition.

PART I-FINANCIAL INFORMATION

Item 1. Financial Statements.

ECA Marcellus Trust I

Statements of Assets, Liabilities, and Trust Corpus

	March 31,			December 31,
	2026			2025
	(Unaudited)
ASSETS:
Cash	$	3,451,035		$	3,234,214
Royalty income receivable		1,792,578			945,495
Royalty interest in gas properties		352,100,000			352,100,000
Accumulated amortization		(343,232,930	)		(342,957,873	)
Net royalty interest in gas properties		8,867,070			9,142,127
Total Assets	$	14,110,683		$	13,321,836

LIABILITIES AND TRUST CORPUS:
Liabilities:
Distributions payable to unitholders	$	1,583,025		$	642,425

Trust Corpus:
Trust corpus; 17,605,000 common units authorized, issued and outstanding		12,527,658			12,679,411
Total Liabilities and Trust Corpus	$	14,110,683		$	13,321,836

See notes to the unaudited financial statements.

ECA Marcellus Trust I

Statements of Distributable Income

(Unaudited)

	Three Months Ended
	March 31,
	2026			2025
Royalty income	$	1,792,578		$	1,278,647
Net proceeds to Trust	$	1,792,578		$	1,278,647

General and administrative expense		(126,268	)		(281,522	)
Interest income		31,373			30,816

Income available for distribution prior to cash reserves	$	1,697,683		$	1,027,940

Cash reserves withheld by Trustee		(90,000	)		(90,000	)
Interest withheld on cash reserves		(24,658	)		(26,420	)
Distributable income available to unitholders	$	1,583,025		$	911,520

Distributable income per common unit
(17,605,000 units authorized and outstanding)	$	0.090		$	0.052

See notes to the unaudited financial statements.

ECA Marcellus Trust I

Statements of Trust Corpus

(Unaudited)

	Three Months Ended
	March 31,
	2026			2025
Trust Corpus, Balance at January 1,	$	12,679,411		$	13,372,881
Cash reserves withheld, including interest		114,658			116,420
Distributable income		1,583,025			911,520
Distributions paid or payable to unitholders		(1,574,380	)		(916,520	)
Amortization of royalty interest in gas properties		(275,056	)		(291,709	)
Impairment of royalty interest in gas properties		-			-
Trust Corpus, Balance at March 31,	$	12,527,658		$	13,192,593

ECA MARCELLUS TRUST I

NOTES TO FINANCIAL STATEMENTS

(Unaudited)

NOTE 1. Organization of the Trust

ECA Marcellus Trust I is a Delaware statutory trust formed in March 2010 by Energy Corporation of America (“Legacy ECA”) to own royalty interests in 14 producing horizontal natural gas wells producing from the Marcellus Shale formation, all of which are online and are located in Greene County, Pennsylvania (the “Producing Wells”), and royalty interests in 52 horizontal natural gas development wells subsequently drilled to the Marcellus Shale formation (the “PUD Wells”) within the “Area of Mutual Interest”, or “AMI”, comprising approximately 9,300 acres held by Legacy ECA, of which it owned substantially all of the working interests, in Greene County, Pennsylvania. The effective date of the Trust was April 1, 2010; consequently, the Trust received the proceeds of production attributable to the PDP Royalty Interest (defined herein) from that date even though the PDP Royalty Interest was not conveyed to the Trust until the closing of the initial public offering on July 7, 2010. The total number of units the Trust is authorized to issue is 17,605,000 units, all of which are now common units. The royalty interests were conveyed from Legacy ECA’s working interest in the Producing Wells and the PUD Wells limited to the Marcellus Shale formation (the “Underlying Properties”). In November 2017, Greylock Energy, LLC and certain of its wholly owned subsidiaries (“Greylock Energy”), including Greylock Production, LLC (“Greylock Production”), which serves as operator of the subject wells, and Greylock Midstream, LLC (“Greylock Midstream”), whose subsidiaries market and gather certain of the gas, acquired substantially of the assets of Legacy ECA, as described in Note 4.

The royalty interest in the Producing Wells (the “PDP Royalty Interest”) entitles the Trust to receive 90% of the proceeds (exclusive of any production or development costs but after deducting post-production costs and any applicable taxes) from the sale of production of natural gas attributable to the Sponsor’s initial interest in the Producing Wells. The royalty interest in the PUD Wells (the “PUD Royalty Interest” and collectively with the PDP Royalty Interest, the “Royalty Interests”) entitles the Trust to receive 50% of the proceeds (exclusive of any production or development costs but after deducting post-production costs and any applicable taxes) from the sale of production of natural gas attributable to the Sponsor’s initial interest in the PUD Wells.

The Trust’s cash receipts in respect of the Royalty Interests are determined after deducting post-production costs and any applicable taxes associated with the Perpetual Royalty Interests. The Trust’s cash available for distribution is reduced by Trust administrative expenses. Post-production costs generally consist of costs incurred to gather, compress, transport, process, treat, dehydrate and market the natural gas produced. Charges (the “Post-Production Services Fee”) for such post-production costs on the Greene County Gathering System (“GCGS”) were limited to $0.52 per MMBtu gathered until Legacy ECA fulfilled its drilling obligation in 2011; since then, the Sponsor has been permitted to increase the Post-Production Services Fee to the extent necessary to recover certain capital expenditures in the GCGS. Additionally, if electric compression is utilized in lieu of gas as fuel in the compression process, royalty proceeds will be reduced for the electric usage as provided for in the Trust conveyance documents.

Gross proceeds to the Trust attributable to the Royalty Interests during the three-month period ended March 31, 2026 were $1.8 million and totaled approximately $4.3 million for the four consecutive quarters ended March 31, 2026. The gross proceeds attributable to the Royalty Interests are dependent upon both the volume of hydrocarbons extracted and sold from the Underlying Properties and the price realized on those sales. The Trust has no control or influence over either the volumes sold or the proceeds realized from those sales. In periods of declining prices, the gross proceeds attributable to the Royalty Interests can be subject to declines. For example, the royalty income to which the Trust is entitled experienced a substantial decline beginning in late 2022, which was driven by lower realized prices and, to a lesser extent, volume declines that are primarily related to the natural production decline inherent in the Underlying Properties. Future volumes or realized pricing or both may not be sufficient to maintain gross proceeds attributable to the Royalty Interests over any four consecutive quarters in excess of $1.5 million.

The trust agreement provides that the Trust will terminate if gross proceeds to the Trust attributable to the Royalty Interests over any four consecutive quarters are less than $1.5 million. If this early termination event occurs, the trust agreement will require the Trustee to sell the Royalty Interests, either by private sale or public auction, subject to Greylock Energy's right of first refusal to purchase the Royalty Interests. After the sale of all of the Royalty Interests, payment of all Trust liabilities and establishment of reasonable provisions for the payment of additional anticipated or contingent Trust expenses or liabilities, the Trustee will distribute the net proceeds of the sale to the Trust unitholders.

The Trust makes quarterly cash distributions of substantially all of its cash receipts, after deducting Trust administrative expenses, including the costs incurred as a result of being a publicly traded entity, on or about the 60^th day following the completion of each quarter. Unless sooner terminated, the Trust will begin to liquidate on or about March 31, 2030 (the “Termination Date”) and will soon thereafter wind up its affairs and terminate. At the termination of the Trust, 50% of each of the PDP Royalty Interest and the PUD Royalty Interest will revert automatically to Greylock Production. The remaining 50% of each of the PDP Royalty Interest and the PUD Royalty Interest will be sold, and the net proceeds will be distributed pro rata to the unitholders soon after the termination of the Trust. Greylock Production will have a right of first refusal to purchase the remaining 50% of the Royalty Interests at the termination of the Trust.

The business and affairs of the Trust are administered by The Bank of New York Mellon Trust Company, N.A., as Trustee. Although Greylock Production operates all of the Producing Wells and all of the PUD Wells, Greylock Production has no ability to manage or influence the management of the Trust. Neither the Trust nor the Trustee has any authority or responsibility for, or any involvement with or influence over, any aspect of the operations on or relating to the properties to which the Royalty Interests relate.

NOTE 2. Basis of Presentation

The preparation of financial statements requires the Trust to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of royalty income and expenses during the reporting period. Without limiting the foregoing statement, the information furnished is based upon certain estimates of the royalty income attributable to the Trust from natural gas production for the three months ended March 31, 2026 and 2025 and is therefore subject to adjustment in future periods to reflect actual production for the periods presented.

The information furnished reflects all normal and recurring adjustments which are, in the opinion of the Trustee, necessary for a fair presentation of the results for the interim period presented. The accompanying unaudited interim financial statements should be read in conjunction with the audited financial statements and notes thereto included in the Trust’s Annual Report on Form 10-K for the year ended December 31, 2025. The December 31, 2025 condensed balance sheet data was derived from audited financial statements, but does not include all applicable financial statement disclosures.

NOTE 3. Significant Accounting Policies

The accompanying unaudited financial information has been prepared by the Trustee in accordance with the instructions to Form 10-Q. The financial statements of the Trust differ from financial statements prepared in accordance with generally accepted accounting principles in the United States of America (“GAAP”) because certain cash reserves may be established for contingencies, which would not be accrued in financial statements prepared in accordance with GAAP. Amortization of the investment in overriding royalty interests calculated on a unit-of-production basis is charged directly to Trust Corpus. This comprehensive basis of accounting other than GAAP corresponds to the accounting permitted for royalty trusts by the U.S. Securities and Exchange Commission (“SEC”) as specified by Accounting Standard Codification (“ASC”) Topic 932, Extractive Activities—Oil and Gas: Financial Statements of Royalty Trusts. Income determined on the basis of GAAP would include all expenses incurred for the period presented. However, the Trust serves as a pass-through entity, with expenses for depreciation, depletion, and amortization, interest and income taxes being based on the status and elections of the Trust unitholders. General and administrative expenses, production taxes or any other allowable costs are charged to the Trust only when cash has been paid for those expenses. In addition, the Royalty Interests are not burdened by field and lease operating expenses. Thus, the statement of distributable income shows distributable income, defined as income of the Trust available for distribution to the Trust unitholders before application of those additional expenses, if any, for depreciation, depletion, and amortization, interest and income taxes. The royalty income is presented net of existing royalties and overriding royalties and have been reduced by gathering/post-production expenses.

Cash:

Cash may include highly liquid instruments maturing in three months or less from the date acquired.

Use of Estimates in the Preparation of Financial Statements:

The preparation of financial statements requires the Trust to make estimates and assumptions that affect the reported amounts of assets and liabilities and the reported amounts of royalty income and expenses during the reporting period. Actual results could differ from those estimates.

Royalty Income and Expenses:

The Trust serves as a pass-through entity, with items of depletion, interest income and expense, and income tax attributes being based upon the status and election of the unitholders. Thus, the Statements of Distributable Income show Income available for distribution before application of those unitholders’ additional expenses, if any, for depletion, interest income and expense, and income taxes.

The Trust uses the accrual basis to recognize royalty income, which is recorded as reserves are extracted from the Underlying Properties and sold. Expenses are recognized when paid.

Royalty Interest in Gas Properties:

The conveyance of the Royalty Interest to the Trust was accounted for as a purchase transaction. The $352,100,000 reflected in the Statements of Assets, Liabilities and Trust Corpus as Royalty interests in gas properties represents 17,605,000 Trust units valued at $20.00 per unit. The carrying value of the Trust’s investment in the Royalty Interests is not necessarily indicative of the fair value of such Royalty Interests.

The Royalty interest in gas properties is assessed to determine whether the net capitalized cost is impaired, whenever events or changes in circumstances indicate that its carrying amount may not be recoverable, pursuant to ASC Topic 360, Property, Plant and Equipment. The Trust determines whether an impairment charge is necessary to its investment in the Royalty interest in gas properties if total capitalized costs, less accumulated amortization, exceed undiscounted future net revenues attributable to proved gas reserves of the Underlying Properties. If required, the Trust will recognize an impairment charge to the extent that the net capitalized costs exceed the discounted fair value of the investment in net profits interests attributable to proved gas reserves of the Underlying Properties. Any such impairment charge would not reduce Distributable Income, although it would reduce Trust Corpus. If an impairment is present, the measurement of an impairment loss involves estimates of fair value, which are determined based on discounted cash flow techniques using assumptions including projected revenues, future commodity prices, production costs, and market-specific average cost of capital. Estimates of undiscounted future net revenues attributable to proved gas reserves utilize estimates of future pricing, which are generally developed based on NYMEX forward pricing curves. No impairment in the Underlying Properties was recognized during 2025 or during the three months ended March 31, 2026. Significant dispositions or abandonment of the Underlying Properties would be charged to Royalty Interests and the Trust Corpus; however, no such dispositions or abandonments occurred during the three-month period ended March 31, 2026.

Amortization of the Royalty interest in gas properties is calculated on a units-of-production basis, whereby the Trust’s cost basis in the properties is divided by Trust total proved reserves to derive an amortization rate per reserve unit. Such amortization does not reduce Distributable Income, rather it is charged directly to Trust Corpus. Revisions to estimated future units-of-production are treated on a prospective basis beginning on the date significant revisions are known.

NOTE 4. Reaffirmation Agreement

On November 29, 2017, Greylock Energy acquired substantially all of the gas production and midstream assets of Legacy ECA, including Legacy ECA’s interests in certain natural gas properties that are subject to royalty interests held by the Trust.

In connection with the transaction, Greylock Production assumed all of Legacy ECA’s obligations under the Amended and Restated Trust Agreement among the Trust, Legacy ECA and the Trustee (the “Trust Agreement”), and other instruments to which Legacy ECA and the Trustee were parties, including (1) the Administrative Services Agreement by and among Legacy ECA, the Trust and the Trustee dated July 7, 2010, and (2) a letter agreement between Legacy ECA and the Trustee regarding certain loans to be made by Legacy ECA to the Trust as necessary to enable the Trust to pay its liabilities as they become due (the “Letter Agreement”). In addition, Legacy ECA, Greylock Production, and the Trustee entered into a Reaffirmation and Amendment of Mortgage, Assignment of Leases, Security Agreement, Fixture Filing and Financing Statement (the “Reaffirmation Agreement”), pursuant to which, among other things, Greylock Production (1) reaffirmed the liens and the security interest granted pursuant to the existing mortgage securing the interests in the subject properties, as well as the mortgage and the obligations of Legacy ECA under the mortgage, and (2) assumed the obligations of Legacy ECA under the Letter Agreement. As of March 31, 2026, no amounts have been loaned to the Trust pursuant to the Letter Agreement.

NOTE 5. Income Taxes

The Trust is a Delaware statutory trust, which is taxed as a partnership for federal and state income taxes. Accordingly, no provision for federal or state income taxes has been made. Uncertain tax positions are accounted for under ASC Topic 740, Income Taxes (“ASC 740”), which prescribes a recognition threshold and measurement attribute for financial statement disclosure of tax positions taken or expected to be taken on a tax return. Additionally, ASC 740 provides guidance on derecognition, classification, interest and penalties, accounting in interim periods, disclosure, and transition. The Trust has not identified any uncertain tax positions through the period ended March 31, 2026.

NOTE 6. Related Party Transactions

Trustee Administrative Fee:

Under the terms of the Trust Agreement, the Trustee charges an annual administrative fee, subject to adjustment each year. The annual fee was $182,202 in 2025 and is $187,668 in 2026. The Trust records these costs, as well as those to be paid to Greylock Production pursuant to the Administrative Services Agreement referred to below, in the period paid.

Administrative Services Fee:

The Trust and Greylock Production are parties to an Administrative Services Agreement that obligates the Trust to pay Greylock Production an administrative services fee for accounting, bookkeeping and informational services performed by Greylock Production on behalf of the Trust relating to the Royalty Interests. The annual fee of $60,000 is payable in equal quarterly installments. Under certain circumstances, Greylock Production and the Trustee each may terminate the Administrative Services Agreement at any time following delivery of notice no less than 90 days prior to the date of termination.

Item 2. Trustee's Discussion and Analysis of Financial Condition and Results of Operations.

References to the “Trust” in this document refer to ECA Marcellus Trust I. As discussed in “Overview” below, Greylock Energy acquired substantially all of the assets of Energy Corporation of America in November 2017. References to “Legacy ECA” in this document refer to Energy Corporation of America and its wholly-owned subsidiaries and, when discussing the conveyance documents, the Private Investors, as such entities existed prior to the asset acquisition by Greylock Energy. The following review of the Trust’s financial condition and results of operations should be read in conjunction with the financial statements and notes thereto and the audited financial statements and notes thereto included in the Trust’s Annual Report on Form 10-K for the year ended December 31, 2025 (the “2025 Form 10-K”). The Trust’s annual reports on Form 10-K, quarterly reports on Form 10-Q, current reports on Form 8-K and all amendments to those reports are available on the SEC’s website at www.sec.gov and at http://ect.q4web.com/home/default.aspx. Certain terms used herein are defined in Appendix A. All information regarding operations has been provided to the Trustee by Greylock Energy.

Note Regarding Forward-Looking Statements

This report contains “forward-looking statements” about Greylock Energy and the Trust and other matters discussed herein that are subject to risks and uncertainties. All statements other than statements of historical fact included in this document, including, without limitation, statements under “Trustee’s Discussion and Analysis of Financial Condition and Results of Operations” and “Risk Factors” regarding the financial position, business strategy, production and reserve growth, development activities and costs and other plans and objectives for the future operations of Greylock Energy and all matters relating to the Trust are forward-looking statements. Actual outcomes and results may differ materially from those projected.

When used in this document, the words “believes,” “expects,” “anticipates,” “intends” or similar expressions, are intended to identify such forward-looking statements. Further, all statements regarding future circumstances or events are forward-looking statements. The following important factors, in addition to those discussed elsewhere in this document, could affect the future results of the energy industry in general, and Greylock Energy and the Trust in particular, and could cause those results to differ materially from those expressed in such forward-looking statements:

risks incident to the operation of natural gas wells;

future production costs;

the effects of existing and future laws and regulatory actions;

the effects of changes in commodity prices;

conditions in the capital markets;

the occurrence or threat of epidemic or pandemic diseases or other public health event or any government response to such occurrence or threat;

the impact of geopolitical developments and tensions, war and uncertainty involving or in the geographical region of oil-producing countries (including the ongoing wars in Ukraine and in the Persian Gulf, and any related political or economic responses and counter-responses or otherwise by various global actors or the general effect on the global economy);

global economic conditions, such as a general slowdown in the global economy, trade barriers and tariffs, supply chain disruptions, inflationary pressures, currency fluctuations, changes in interest rates, and instability of financial institutions;

competition in the energy industry;

the uncertainty of estimates of natural gas reserves and production;

potential impacts on Greylock Energy’s business resulting from climate change, greenhouse gas regulations, and the impact of climate change related changes in the frequency and severity of weather patterns; and

other risks described under the caption “Risk Factors” in Part I, Item 1A of the 2025 Form 10-K.

This report describes other important factors that could cause actual results to differ materially from expectations of Greylock Energy and the Trust. All subsequent written and oral forward-looking statements attributable to Greylock Energy or the Trust or persons acting on behalf of Greylock Energy or the Trust are expressly qualified in their entirety by such factors. The Trust assumes no obligation, and disclaims any duty, to update these forward-looking statements.

Overview

The Trust is a statutory trust created under the Delaware Statutory Trust Act. The Bank of New York Mellon Trust Company, N.A. serves as Trustee. The Trust does not conduct any operations or activities. The Trust’s purpose is, in general, to hold the Royalty Interests (described below), to distribute to the Trust unitholders cash that the Trust receives in respect of the Royalty Interests after payment of Trust expenses, and to perform certain administrative functions in respect of the Royalty Interests and the Trust units. The Trustee has no authority or responsibility for, and no involvement with, any aspect of the oil and gas operations on the properties to which the Royalty Interests relate. The Trust derives all or substantially all of its income and cash flows from the Royalty Interests. The Trust is treated as a partnership for federal and state income tax purposes.

In November 2017, Greylock Energy and certain of its wholly owned subsidiaries, including Greylock Production, LLC, which serves as operator of the subject wells, and Greylock Midstream, LLC, whose subsidiaries market and gather certain of the gas, acquired substantially all of the gas production and midstream assets of Legacy ECA, including all of Legacy ECA’s interests in certain natural gas properties that are subject to royalty interests held by the Trust.

In connection with the transaction, Greylock Production assumed all of Legacy ECA’s obligations under the Trust Agreement and other instruments to which Legacy ECA and the Trustee were parties, including (1) the Administrative Services Agreement by and among Legacy ECA, the Trust and the Trustee dated July 7, 2010, and (2) a letter agreement between Legacy ECA and the Trustee regarding certain loans to be made by Legacy ECA to the Trust as necessary to enable the Trust to pay its liabilities as they become due (the “Letter Agreement”). In addition, Legacy ECA, Greylock Production, and the Trustee entered into a Reaffirmation and Amendment of Mortgage, Assignment of Leases, Security Agreement, Fixture Filing and Financing Statement (the “Reaffirmation Agreement”), pursuant to which, among other things, Greylock Production (1) reaffirmed the liens and the security interest granted pursuant to the existing mortgage securing the interests in the subject properties, as well as the mortgage and the obligations of Legacy ECA under the mortgage, and (2) assumed the obligations of Legacy ECA under the Letter Agreement.

The Royalty Interests were conveyed to the Trust from the working interest now held by Greylock Production in the Producing Wells and the PUD Wells limited to the Underlying Properties. The PDP Royalty Interest entitles the Trust to receive 90% of the proceeds (exclusive of any production or development costs but after deducting post-production costs and any applicable taxes) from the sale of production of natural gas attributable to the Sponsor’s initial interest in the Producing Wells for a period of 20 years commencing on April 1, 2010 and 45% thereafter. The PUD Royalty Interest entitles the Trust to receive 50% of the proceeds (exclusive of any production or development costs but after deducting post-production costs and any applicable taxes) from the sale of production of natural gas attributable to the Sponsor’s initial interest in the PUD Wells for a period of 20 years commencing on April 1, 2010 and 25% thereafter.

Legacy ECA was obligated to drill all of the PUD Wells by March 31, 2014. As of November 30, 2011, Legacy ECA had fulfilled its drilling obligation to the Trust by drilling 40 PUD Wells (52.06 Equivalent PUD Wells), calculated as provided in the Development Agreement. Consequently, no additional wells will be drilled for the Trust. The Trust was not responsible for any costs related to the drilling of development wells or any other development or operating costs. As of September 30, 2025, the Trust owns royalty interests in 14 Producing Wells and the 40 development wells (52.06 Equivalent PUD Wells) that are now completed and in production.

The cash received by the Trust in respect of the Royalty Interests are determined after deducting post-production costs and any applicable taxes associated with the Royalty Interests, and the Trust’s cash available for distribution is reduced by Trust administrative expenses and any amounts reserved for administrative expenses. Post-production costs generally consist of costs incurred to gather, compress, transport, process, treat, dehydrate and market the natural gas produced. Charges (the “Post-Production Services Fee”) for such post-production costs on the related GCGS were limited to $0.52 per MMBtu gathered until Legacy ECA fulfilled its drilling obligation in 2011; since then the Sponsor has been permitted to increase the Post-Production Services Fee to the extent necessary to recover certain capital expenditures in the GCGS.

The Sponsor and Columbia Gas Transmission, LLC (“Columbia”) are parties to a transportation agreement (the “Transportation Agreement”), in effect since August 1, 2011, that provides for firm transportation downstream of the GCGS at Columbia’s filed tariff rate. During the third quarter of 2024, Greylock Production and Columbia amended the Transportation Agreement to reduce the firm transportation amount, from 45,000 MMBtu per day that had initially prevailed under the agreement, to 39,901 MMBtu per day effective January 1, 2025 through December 31, 2027.

The tariff rates under the Transportation Agreement that had been in effect from December 1, 2021 through March 31, 2025 were set in 2022 pursuant to a settlement between Columbia and certain shippers in proceedings before the Federal Energy Regulatory Commission (“FERC”) and had been approximately $0.35 per MMBtu at one hundred percent load factor from April 2024 through March 31, 2025. On September 30, 2024, Columbia submitted an application to FERC to increase certain tariff rates effective April 1, 2025. On October 31, 2024, FERC issued an Order Accepting and Suspending the Filing, Subject to Refund. As filed, the tariff rate increased from approximately $0.35 per MMBtu to approximately $0.725 per MMBtu on the applicable contracts. Columbia began charging the increased transportation rates effective April 1, 2025. Greylock Production and other parties protested the new proposed tariff rate at FERC. On July 1, 2025, Columbia moved to place the Period I Settlement Rates into effect as of June 1, 2025 and apply such rates to the settling parties, including Greylock Production. The Chief Administrative Law Judge granted Columbia’s motion. Columbia invoiced Greylock Production at the one hundred percent load factor tariff rate of $0.4436 per MMBtu for June 2025. On August 13, 2025, Columbia filed a proposed final settlement at FERC. On September 15, 2025, the Presiding Administrative Law Judge certified the settlement as uncontested with a tariff rate of $0.4376 per MMBtu from April 1, 2025 to March 31, 2026 and increasing by $0.0075 per MMBtu annually (through March 31, 2028). FERC approved the settlement on October 30, 2025. Columbia issued refunds on the difference between the initial increased rates charged for April and May 2025 and the final settlement rate. During the first quarter of 2026, Greylock Production distributed to the Trust approximately $30,000 representing the portion of the refund attributable to the Trust, along with the royalty income attributable to the fourth quarter of 2025.

Firm transportation utilized as to the Trust’s interests is a chargeable post-production cost, and the Trust bears its proportionate share of such costs; however, the Trust was not charged for the costs associated with modifying the Transportation Agreement with Columbia.

Greylock Production may enter into similar gas supply arrangements and post-production service arrangements for the natural gas to be produced from the Underlying Properties. Any new gas supply arrangements or those entered into for providing post-production services, will be utilized in determining the proceeds for the Underlying Properties. Accordingly, to the extent that the cost of any new gas supply arrangements exceeds the cost under existing arrangements, proceeds to the Trust could decline and any such decline could be material.

Generally, the percentage of production proceeds to be received by the Trust with respect to a well equals the product of (i) the percentage of proceeds to which the Trust is entitled under the terms of the conveyances (90% for the Producing Wells and 50% for the PUD Wells) multiplied by (ii) Greylock Production’s net revenue interest in the well. Greylock Production on average owns an 81.53% net revenue interest in the Producing Wells. Therefore, the Trust is entitled to receive on average 73.37% of the proceeds of production from the Producing Wells. With respect to the PUD Wells, the conveyance related to the PUD Royalty Interest provides that the proceeds from the PUD Wells will be calculated on the basis that the underlying PUD Wells are burdened only by interests that in total would not exceed 12.5% of the revenues from such properties, regardless of whether the royalty interest owners are actually entitled to a greater percentage of revenues from such properties. As an example, assuming Greylock Production owns a 100% working interest in a PUD Well, the applicable net revenue interest is calculated by multiplying Greylock Production’s percentage working interest in the 100% working interest well by the unburdened interest percentage (87.5%), and such well would have a minimum 87.5% net revenue interest. Accordingly, the Trust is entitled to a minimum of 43.75% of the production proceeds from the well provided in this example. To the extent Greylock Production’s working interest in a PUD Well is less than 100%, the Trust’s share of proceeds would be proportionately reduced.

The Trust makes quarterly cash distributions of substantially all of its cash receipts, after deducting Trust administrative expenses and costs and reserves therefor, on or about the 60^th day following the completion of each quarter. Unless sooner terminated, the Trust will begin to liquidate in March 2030 and will soon thereafter wind up its affairs and terminate.

The amount of Trust royalty income and cash distributions to Trust unitholders depends on, among other things:

natural gas prices received;

the volume and Btu rating of natural gas produced and sold;

post-production costs and any applicable taxes; and

administrative expenses of the Trust including expenses incurred as a result of being a publicly traded entity and any changes in amounts reserved for such expenses.

The markets for natural gas are volatile. The outbreak of war between Russia and Ukraine in February 2022 and the subsequent sanctions imposed on Russia and other actions have created significant market uncertainties, including uncertainties around potential supply disruption for oil and natural gas, which has further enhanced the volatility in natural gas prices since early 2022. In addition, the ongoing war with Iran also could have a disruptive effect on global natural gas markets. The extent and duration of the wars in Ukraine and the Persian Gulf, sanctions and resulting market disruptions could be significant, including significant volatility in commodity prices, supply of energy resources, instability in financial markets, supply chain interruptions, political and social instability, changes in consumer or purchaser preferences as well as increases in cyberattacks and espionage, each of which could have a substantial impact on the global economy and consequently the Trust’s business for an unknown period of time. Although the events in Ukraine and the Middle East are not currently expected to have a material impact on the Trust’s business, cash flows, liquidity or financial condition, neither Greylock Energy nor the Trustee can predict the progress or outcome of the wars in Ukraine or the Persian Gulf, as these conflicts, and any resulting government reactions, are evolving and beyond the control of Greylock Energy or the Trust. Meanwhile, economic conditions, such as inflation or higher unemployment rates, or changes in economic policies, such as further increases in tariffs or trade barriers, could affect the demand for natural gas. As a result of these and other factors, prices for natural gas, and therefore the Trust’s quarterly cash distributions, might not be maintained for any significant period. Low natural gas prices will reduce royalty income to the Trust, which will reduce the amount of cash available for distribution to unitholders and in certain periods could result in no distributions to unitholders. For example, there was no distribution to unitholders for the quarter ended June 30, 2024 as Trust expenses exceeded net revenues to the Trust.

The effective date of the Trust was April 1, 2010, meaning the Trust has received the proceeds of production attributable to the PDP Royalty Interest from that date even though the PDP Royalty Interest was not conveyed to the Trust until July 7, 2010. The amount of the quarterly distributions fluctuates from quarter to quarter, depending on the proceeds received by the Trust, among other factors. There is no minimum required distribution.

Gross proceeds to the Trust attributable to the Royalty Interests during the three-month period ended March 31, 2026 were $1.8 million and totaled approximately $4.3 million for the four consecutive quarters ended March 31, 2026. The gross proceeds attributable to the Royalty Interests are dependent upon both the volume of hydrocarbons extracted and sold from the Underlying Properties and the price realized on those sales. The Trust has no control or influence over either the volumes sold or the proceeds realized from those sales. The royalty income to which the Trust is entitled has experienced a substantial decline beginning in late 2022, which has been driven by lower realized prices and, to a lesser extent, volume declines that are primarily related to the natural production decline inherent in the Underlying Properties. Future volumes or realized pricing or both may not be sufficient to maintain gross proceeds attributable to the Royalty Interests over any four consecutive quarters in excess of $1.5 million.

Pursuant to Section 1446 of the Internal Revenue Code of 1986 (the “IRC”), withholding tax on income effectively connected to a United States trade or business allocated to non-U.S. persons (“ECI”) should be made at the highest marginal rate. Under IRC Section 1441, withholding tax on fixed, determinable, annual, periodic income from United States sources allocated to non-U.S. persons should be made at a 30% rate unless the rate is reduced by treaty. Nominees and brokers should withhold at the highest marginal rate on the distribution made to non-U.S. persons. A non-U.S. holder’s gain on the sale of Trust units is treated as ECI to the extent such holder would have had ECI if the Trust had sold all of its assets at fair market value on the date of the sale of such Trust units. A transferee of units is also required to withhold 10% of the amount realized on the sale or exchange of units (generally, the purchase price) unless the transferor certifies that it is not a nonresident alien individual or foreign corporation or another exception is available.

Results of Trust Operations

For the Three Months Ended March 31, 2026 compared to the Three Months Ended March 31, 2025

Distributable income for the three months ended March 31, 2026 increased to $1.6 million from $0.9 million for the three months ended March 31, 2025. Compared to the quarter ended March 31, 2025, royalty income increased by $0.5 million while administrative expenses decreased approximately $0.2 million.

Royalty income increased to $1.8 million for the three months ended March 31, 2026 from $1.3 million for the three months ended March 31, 2025. Between periods, there were increases in the average sales price realized and in production.

The average price realized for the three months ended March 31, 2026 increased $1.09 per Mcf to $3.99 per Mcf compared to $2.90 per Mcf for the three months ended March 31, 2025. The increase in the average sales price realized for natural gas production was due to a higher average sales price and a decrease in the average rate for other post-production costs. The average sales price, before post-production costs, increased from $3.50 per Mcf for the three months ended March 31, 2025 to $4.58 per Mcf for the three months ended March 31, 2026. The increase in price was the result of an increase in the average monthly closing NYMEX price, partially offset by an increase in the average negative basis. The weighted average monthly closing NYMEX price for the three months ended March 31, 2026 was $4.84 per MMBtu compared to the weighted average monthly closing NYMEX price of $3.65 per MMBtu for the three months ended March 31, 2025. The average Basis per MMBtu realized for the three months ended March 31, 2026 was minus $0.40 per MMBtu compared to minus $0.25 per MMBtu for the three months ended March 31, 2025.

Post-production costs consist of a post-production services fee together with a charge for electricity used in lieu of gas for compression on the gathering system and firm transportation charges on interstate gas pipelines. Average post-production costs were $0.59 per Mcf for the three months ended March 31, 2026 compared to $0.60 per Mcf for the three months ended March 31, 2025.

Production increased 1.9% from 441 MMcf for the three months ended March 31, 2025 to 450 MMcf for the three months ended March 31, 2026.

General and administrative expenses paid by the Trust were $0.1 million and $0.3 million for the three-month periods ended March 31, 2026 and 2025, respectively. Cash reserves of $0.1 million were withheld for each of the three-month periods ended March 31, 2026 and March 31, 2025.

Liquidity and Capital Resources

The Trust has no source of liquidity or capital resources other than net cash flows from the Royalty Interests. Other than Trust administrative expenses, including, if applicable, expense reimbursements to Greylock Production and any reserves established by the Trustee for future liabilities, the Trust’s only use of cash is for distributions to Trust unitholders. Administrative expenses include payments to the Trustee and the Delaware Trustee as well as a quarterly fee of $15,000 to Greylock Production pursuant to the Administrative Services Agreement. Each quarter, the Trustee determines the amount of funds available for distribution. Available funds are the excess cash, if any, received by the Trust from the Royalty Interests and other sources (such as interest earned on any amounts reserved by the Trustee) that quarter, over the Trust’s expenses for that quarter. Available funds are reduced by any cash the Trustee determines to hold as a reserve against future expenses or liabilities. The Trustee, on behalf of the Trust, may borrow funds required to pay expenses or liabilities if the Trustee determines that the cash on hand and the cash to be received are insufficient to cover the Trust’s expenses or liabilities. If the Trustee borrows funds, the Trust unitholders will not receive distributions until the borrowed funds are repaid.

Since the first quarter of 2019, the Trustee has been gradually building a cash reserve for the payment of future expenses and liabilities of the Trust by withholding cash reserve amounts from each quarterly distribution. In November 2021, the Trustee notified the Sponsor that the Trustee had determined to increase the targeted cash reserve from the initially stated amount of approximately $1.8 million, to approximately $3.8 million. From the first quarter of 2019 through the fourth quarter of 2022, the Trustee withheld an amount from each distribution equal to the greater of $90,000 or 10% of the amount distributable to unitholders. Since achieving the initial target of $1.8 million in the quarter ended December 31, 2022, the Trustee has been withholding, and currently plans to continue to withhold, $90,000 per quarter until a total of approximately $3.8 million in cash reserves is withheld. For the quarter ended March 31, 2026, the Trustee withheld $90,000 from the funds otherwise available for distribution and withheld a minimal amount of interest earned on the cash reserve balance. As of March 31, 2026, the Trustee has withheld from the funds otherwise available for distribution a total amount of approximately $2.8 million plus $0.4 million of interest toward the building of the $3.8 million cash reserve. These withholdings are in addition to the existing cash reserve of $0.5 million, which is determined prior to the payments of quarterly expenses. The Trustee may increase or decrease the targeted amount at any time, and may increase or decrease the rate at which it is withholding funds to build the cash reserve at any time, without advance notice to the unitholders.

Payments to the Trust in respect of the Royalty Interests are based on the complex provisions of the various conveyances held by the Trust, copies of which are filed as exhibits to the 2024 Form 10-K, and reference is hereby made to the text of the conveyances for the actual calculations of amounts due to the Trust.

The Trust does not have any transactions, arrangements or other relationships with unconsolidated entities or persons that could materially affect the Trust’s liquidity or the availability of capital resources.

Critical Accounting Policies and Estimates

The financial statements of the Trust differ from financial statements prepared in accordance with generally accepted accounting principles in the United States of America (“GAAP”) because, among other differences, certain cash reserves may be established for contingencies, which would not be accrued in financial statements prepared in accordance with GAAP. Amortization of the investment in overriding royalty interests calculated on a unit-of-production basis is charged directly to Trust Corpus. This comprehensive basis of accounting other than GAAP corresponds to the accounting permitted for royalty trusts by the SEC as specified by ASC Topic 932 Extractive Activities—Oil and Gas: Financial Statements of Royalty Trusts.

Income determined on the basis of GAAP would include all expenses incurred for the period presented. However, the Trust serves as a pass-through entity, with expenses for depreciation, depletion, and amortization, interest and income taxes being based on the status and elections of the Trust unitholders. General and administrative expenses, production taxes or any other allowable costs are charged to the Trust only when cash has been paid for those expenses. In addition, the Royalty Interests are not burdened by field and lease operating expenses. Thus, the statement of distributable income shows distributable income, defined as income of the Trust available for distribution to the Trust unitholders before application of those unitholders’ additional expenses, if any, for depreciation, depletion, and amortization, interest and income taxes. The royalty income is reflected net of existing royalties and overriding royalties and have been reduced by gathering/post-production expenses.

Royalty Income and Expenses:

The Trust serves as a pass-through entity, with items of depletion, interest income and expense, and income tax attributes being based upon the status and election of the unitholders. Thus, the Statements of Distributable Income show income available for distribution before application of those unitholders’ additional expenses, if any, for depletion, interest income and expense, and income taxes.

The Trust uses the accrual basis to recognize revenue, with royalty income recorded as reserves are extracted from the Underlying Properties and sold. Expenses are recognized when paid.

Royalty Interest in Gas Properties:

Item 3. Quantitative and Qualitative Disclosures about Market Risk.

As a “smaller reporting company” as defined in Item 10 of Regulation S-K, the Trust is not required to provide information required by this Item.

Item 4. Controls and Procedures.

Evaluation of Disclosure Controls and Procedures. The Trustee maintains disclosure controls and procedures designed to ensure that information required to be disclosed by the Trust in the reports that it files or submits under the Securities Exchange Act of 1934, as amended (the “Act”), is recorded, processed, summarized and reported within the time periods specified in the SEC’s rules and forms promulgated by the SEC. Disclosure controls and procedures include controls and procedures designed to ensure that information required to be disclosed by the Trust in the reports that it files or submits under the Act is accumulated and communicated by Greylock Production to The Bank of New York Mellon Trust Company, N.A., as Trustee of the Trust, and its employees who participate in the preparation of the Trust’s periodic reports as appropriate to allow timely decisions regarding required disclosure.

As of the end of the period covered by this report, the Trustee carried out an evaluation of the Trustee’s disclosure controls and procedures. Sarah Newell, as Trust Officer of the Trustee, has concluded that the disclosure controls and procedures of the Trust are effective.

Certain characteristics of the Trust may limit the effectiveness of the disclosure controls and procedures established by the Trustee. The limitations include the facts that:

Greylock Production and its consolidated subsidiaries manage virtually all of the information relating to the Trust, including all information regarding (i) historical operating data, production volumes, the number of producing wells and acreage, the marketing and sale of production, operating and capital expenditures, environmental matters and other potential expenses and liabilities, and the effects of regulatory matters and changes, (ii) plans for future operating and capital expenditures and (iii) geological data relating to reserves, and the Trustee necessarily relies on Greylock Production for all such information; and

The Trustee necessarily relies upon the independent reserve engineer as an expert with respect to the annual reserve report, which includes projected production, operating expenses and capital expenses.

Other than reviewing the financial and other information provided to the Trust by Greylock Production and the independent reserve engineer, the Trustee has made no independent or direct verification of this financial or other information.

The Trustee does not intend to expand its responsibilities beyond those permitted or required by the Trust Agreement and those required under applicable law.

The Trustee does not expect that the Trustee’s disclosure controls and procedures or the Trustee’s internal control over financial reporting will prevent all errors or all fraud. Further, the design of disclosure controls and procedures and internal control over financial reporting must reflect the fact that there are resource constraints, and the benefits of controls must be considered relative to their costs. Because of the inherent limitations in all control systems, no evaluation of controls can provide absolute assurance that all control issues and instances of fraud, if any, have been detected.

Changes in Internal Control over Financial Reporting. During the quarter ended March 31, 2026, there was no change in the Trustee’s internal control over financial reporting that has materially affected, or is reasonably likely to materially affect, the Trustee’s internal control over financial reporting relating to the Trust. The Trustee notes for purposes of clarification that it has no authority over, and makes no statement concerning, the internal control over financial reporting of Greylock Energy.

PART II-OTHER INFORMATION

Item 1A. Risk Factors.

Risk factors relating to the Trust are contained in Item 1A of the 2025 Form 10-K. No material changes to such risk factors have occurred since the filing of such report.

Item 5. Other Information.

Rule 10b5-1 Trading Plans. During the three months ended March 31, 2026, no officer or employee of the Trustee who performs policy-making functions for the Trust adopted, modified, or terminated any Rule 10b5-1 trading arrangement or non-Rule 10b5-1 trading arrangement, as such terms are defined in Item 408(a) of Regulation S-K, with respect to the Trust units.

Item 6. Exhibits.

The exhibits below are filed or furnished herewith or incorporated herein by reference.

Exhibit Number	Description
3.1		Certificate of Trust of ECA Marcellus Trust I (Incorporated herein by reference to Exhibit 3.1 to Registration Statement on Form S-1 (Registration No. 333-165833))
3.2		Amended and Restated Trust Agreement of ECA Marcellus Trust I, dated July 7, 2010, by and among Energy Corporation of America, The Bank of New York Mellon Trust Company, N.A., as Trustee, and Corporation Trust Company, as Delaware Trustee. (Incorporated herein by reference to Exhibit 3.1 to the Trust’s Current Report on Form 8-K filed on July 13, 2010 (File No. 001-34800))
31		Certification pursuant to Section 302 of the Sarbanes-Oxley Act of 2002
32		Certification pursuant to Section 906 of the Sarbanes-Oxley Act of 2002

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned thereunto duly authorized.

ECA MARCELLUS TRUST I

By:	THE BANK OF NEW YORK MELLON TRUST
	COMPANY, N.A., trustee

	By:	/s/ SARAH NEWELL
		Sarah Newell
		Vice President

Date: May 13, 2026

The registrant, ECA Marcellus Trust I, has no principal executive officer, principal financial officer, board of directors or persons performing similar functions. Accordingly, no additional signatures are available, and none have been provided. In signing the report above, the Trustee does not imply that it has performed any such function or that such function exists pursuant to the terms of the trust agreement under which it serves.

APPENDIX A

GLOSSARY OF CERTAIN TERMS

The following are definitions of certain significant terms used in this report. Other terms are defined in the text of this report.

AMI - The area of mutual interest, or AMI, consisted of the Marcellus Shale formation in approximately 121 square miles of property located in Greene County, Pennsylvania in which Legacy ECA had leased approximately 9,300 acres and owned substantially all of the working interests at the date of formation of the Trust. Legacy ECA was obligated to drill the 52 development wells from drill sites on approximately 9,300 leased acres in the AMI. Until Legacy ECA satisfied its drilling obligation on November 30, 2011, it was not permitted to drill and complete any well in the Marcellus Shale formation within the AMI for its own account.

Basis - The difference between the spot or cash price and the futures price of the same or related commodity. For natural gas, basis equals the local cash market price minus the price of the nearby NYMEX natural gas futures contract.

Completion - (or its derivatives) means that the well has been perforated, stimulated, tested and permanent equipment for the production of natural gas has been installed.

Development Agreement - An agreement under which Legacy ECA was obligated to drill all of the PUD Wells no later than March 31, 2014. In order to secure the estimated amount of the drilling costs for the Trust’s interests in the PUD Wells, Legacy ECA granted to the Trust a lien on Legacy ECA’s interest in the Marcellus Shale formation in the AMI, excluding the Producing Wells and any other wells which were producing and not subject to the Royalty Interests.

Equivalent PUD Well - is defined as a well that is drilled horizontally in the Marcellus formation for a lateral distance of 2,500 feet measured from the midpoint of the curve to the end of the lateral multiplied by the working interest held by Legacy ECA. Wells with a horizontal lateral less than 2,500 feet count as fractional wells in proportion to the total lateral length divided by 2,500 feet. Wells with a horizontal lateral greater than 2,500 feet (subject to a maximum of 3,500 feet) count as fractional wells in proportion to the total lateral length divided by 2,500 feet.

Gas - means natural gas and all other gaseous hydrocarbons, excluding condensate, butane, and other liquid and liquefiable components that are actually removed from the Gas stream by separation, processing or other means.

MMBtu - One million British Thermal Units.

Mcf - One thousand cubic feet of natural gas.

MMcf - One million cubic feet of natural gas.

Perpetual Royalty Interests - a term that collectively references the Perpetual PDP Royalty Interests and the Perpetual PUD Royalty Interests.

Private Investors - the persons described as the “Private Investors” in the Prospectus.

Prospectus - the prospectus dated July 1, 2010 and filed on July 1, 2020 with the SEC pursuant to Rule 424(b) under the Securities Act of 1933, as amended, relating to the initial public offering of the Trust units.

SEC - means the United States Securities and Exchange Commission.

Subject Gas - means Gas from the Marcellus Shale formation from any Producing Well or PUD Well.

Working Interest - The right granted to the lessee of a property to explore for and to produce and own oil, gas, or other minerals. The working interest owners bear the exploration, development and operating costs on either a cash, penalty or carried basis.

ECA Marcellus Trust I 10-Q